22 THE DATE PALM. 



lower level beyond the reach of the young roots. The area about the 

 ofl'shoot inclosed by the borders should then be covered with straw to 

 a depth of a foot. This mulch will hinder evaporation and thereby 

 restrict the rise of alkali, since each application of water washes the 

 alkali down anew and the mulch continues to act as a check on evapo- 

 ration. Such a method of planting should be adopted in those parts 

 of the Salton Basin where there is danger of a rise of alkali from the 

 subsoil. 



DISTANCES BETWEEN TREES. 



The Arabs almost invariably plant the date palm without any attempt 

 at placing the young ofl'shoots in definite order. The result is, it is 

 almost impossible for them to be sure of planting the trees at any con- 

 stant distance from each other, some being close together, others wide 

 apart, as can be seen in Plates XII and XIII. 



The unsystematic and frequently careless methods employed by the 

 Arabs in the culture of the date palm can not be taken as models to be 

 followed in introducing the date industry into the Southwest; we should 

 rather follow the example of the French colonists in the Sahara, who 

 plant the date palm in regular rows (see PL XVII, fig. 1), and have, 

 as a rule, definitely planned and carefully executed systems of irriga- 

 tion and drainage. Although the Arabs plant the date palms very 

 close together, the French have found it advisable to place the trees 

 wide apart, and many of the French colonists regret having placed 

 the trees only 20 or 22 feet apart, their opinion now being that date 

 palms should be planted from 26 to 33 feet from each other. 



Ben Chabat, an Arab, who is considered an authority on date cul- 

 ture, makes two date palms speak together; one says to the other, 

 " Take thy shadow away from mine and I will produce alone for us two 

 together" expressing the idea that too close planting is dangerous. 

 At 26 feet apart, which may be taken as an average distance, about 60 

 palms would be planted on an acre. If the palms are put 30 feet or 

 more apart other crops can be grown between the trees even when old. 



The amount of irrigation water available during the hot season and 

 the value of land are factors which must be considered in deciding 

 at what distance the offshoots should be planted. In general the far- 

 ther apart the palms are, the more heat and light each receives, and 

 the better and the more abundant is their fruit. 



Even when planted 26 feet apart or less there are, of course, large 

 strips which lie unused between the palm trees for the first ten or 

 twelve years after planting. It has become a common practice in the 

 Algerian Sahara, copying to some extent after the Arabs, to plant 

 garden or field crops between the trees until the palm trees become 

 large enough to shade the ground. In case the soil is alkaline, it is 



"Masselot, F. Bui. Direction Agric. et Comm., Tunis, vol. 6 (1891), No. 19, 



